<template>

  <div class="app-container">

    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>

    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>

      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类" @change="subjectLevelOneChanged">
          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="请选择">
          <el-option
            v-for="subject in subjectTwoList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>

      <!-- 课程讲师 TODO -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          placeholder="请选择">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>
        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>

      <!-- 课程简介 TODO -->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>

      <!-- 课程封面 TODO -->
      <el-form-item label="课程封面">

        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduoss/fileoss'"
          class="avatar-uploader">
          <img :src="courseInfo.cover">
        </el-upload>

      </el-form-item>

      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
      </el-form-item>

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
  import course from '@/api/edu/course'
  //引入组件
  import Tinymce from '@/components/Tinymce'
  // import subject from '@/api/edu/subject'
  export default {
    name: 'info',
    //声明组件
    components: { Tinymce },
    data(){
      return{
        courseInfo:{
          id:'',
          title: '',
          subjectId: '',
          subjectParentId:'',
          teacherId: '',
          lessonNum: 0,
          description: '',
          cover: '/static/11.jpg',
          price: 0
        },
        BASE_API:process.env.BASE_API,
        teacherList:{},
        subjectOneList:{},
        subjectTwoList:{},
        courseId:''
      }
    },
    created(){
      //判断路由中是否有值
     this.init();
    },
    watch:{
      $route(to,from){
        this.init();
      }
    },
    methods:{
      init(){
        if (this.$route.params && this.$route.params.id){
          this.courseId=this.$route.params.id;
          this.getInfo();
        }else {
          this.getListTeacher();
          this.getOneSubject();
          this.courseInfo={
            title: '',
            subjectId: '',
            subjectParentId:'',
            teacherId: '',
            lessonNum: 0,
            description: '',
            cover: '/static/11.jpg',
            price: 0
          };
        }

      },
      //根据id查询信息
      getInfo(){
        course.getCourseInfo(this.courseId).then(r=>{
          this.courseInfo=r.data.courseInfoVo;
          //查询所以的分类
          course.getSubject().then(r=>{
            //获取一级分类
            this.subjectOneList=r.data.list;
            //将所以一级分类进行遍历
            for (var i=0;i<this.subjectOneList.length;i++){
              var oneSubject=this.subjectOneList[i]
              if (this.courseInfo.subjectParentId==oneSubject.id){
                this.subjectTwoList=oneSubject.children
              }
            }
          })
          this.getListTeacher();
        })
      },
      //上传封面成功
      handleAvatarSuccess(res,file){
        this.courseInfo.cover=res.data.url;
      },
      //上传之前
      beforeAvatarUpload(file){
        const isJPG = file.type === 'image/jpeg'
        const isLt2M = file.size / 1024 / 1024 < 2

        if (!isJPG) {
          this.$message.error('上传头像图片只能是 JPG 格式!')
        }
        if (!isLt2M) {
          this.$message.error('上传头像图片大小不能超过 2MB!')
        }
        return isJPG && isLt2M
      },
      //当我们点击一级分类触发的二级分类
      subjectLevelOneChanged(value){
        for (let i = 0; i < this.subjectOneList.length; i++) {
          if (this.subjectOneList[i].id === value) {
            this.subjectTwoList = this.subjectOneList[i].children
            this.courseInfo.subjectId = ''
          }
        }

      },
      //查询一级分类
      getOneSubject(){
          course.getSubject().then(r=>{
            this.subjectOneList=r.data.list
          })
      },
      //查询讲师
      getListTeacher(){
        course.getListTeacher().then(r=>{
          this.teacherList=r.data.items
        })
      },
      //添加
      addCourse(){
        course.addCourseInfo(this.courseInfo).then(r=>{
          if (r.code==20000) {
            this.$message({
              type:'success',
              message:r.message
            })
            this.$router.push({path:'/course/chapter/'+r.data.courseId})
          }else {
            this.$message({
              type:'error',
              message:r.message
            })
          }
        })
      },
      updateCourse(){
        course.updateCourseInfo(this.courseInfo).then(r=>{
          if (r.code==20000) {
            this.$message({
              type:'success',
              message:r.message
            })
            this.$router.push({path:'/course/chapter/'+this.courseId})
          }else {
            this.$message({
              type:'error',
              message:r.message
            })
          }
        })
      },
      saveOrUpdate(){
        if(this.courseId !=''){
          this.updateCourse();
        }else {
          this.addCourse()
        }
        //跳转到第二步
        // course.addCourseInfo(this.courseInfo).then(r=>{
        //   if (r.code==20000) {
        //     this.$message({
        //       type:'success',
        //       message:r.message
        //     })
        //     this.$router.push({path:'/course/chapter/'+r.data.courseId})
        //   }else {
        //     this.$message({
        //       type:'error',
        //       message:r.message
        //     })
        //   }
        // })
      },
    }
  }
</script>

<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>
